Quality of Life Changes Following the Onset of Cerebellar Ataxia: Symptoms and Concerns Self-reported by Ataxia Patients and Informants.

Semi-structured interviews of patient accounts and caregiver, or informant, perspectives are a beneficial resource for patients suffering from diseases with complex symptomatology, such as cerebellar ataxia. The aim of this study was to identify, quantify, and compare the ways in which cerebellar ataxia patients' and informants' quality of life had changed as a result of living with ataxia. Using a semi-structured interview, responses were collected from patients and informants regarding motor, cognitive, and psychosocial variables. Responses were also collected from patients and informants to open-ended questions that were subsequently categorized into 15 quality of life themes that best represented changes experienced by the patients and informants. Ataxia patients and informants agreed as to the severity of posture/gait, daily activities/fine motor tasks, speech/feeding/swallowing, and oculomotor/vision impairment. It was also demonstrated that severity ratings for specific motor-related functions strongly correlated with corresponding functions within the International Cooperative Ataxia Rating Scale (ICARS), and that this interview identified frequency associations between motor impairments and specific psychosocial difficulties, which could be useful for prognostic purposes. Overall, the information obtained from this study characterized the symptoms and challenges to ataxia patients and their caregivers, which could serve as a useful educational resource for those affected by ataxia, clinicians, and researchers.

The Cerebellum and Implicit Sequencing: Evidence from Cerebellar Ataxia.

The cerebellum recognizes sequences from prior experiences and uses this information to generate internal models that predict future outcomes in a feedforward manner [Front Hum Neurosci 8: 475, 2014; Cortex 47: 137-44, 2011; Cerebellum 7: 611-5, 2008; J Neurosci 26: 9107-16, 2006]. This process has been well documented in the motor domain, but the cerebellum's role in cognitive sequencing, within the context of implicit versus explicit processes, is not well characterized. In this study, we tested individuals with cerebellar ataxia and healthy controls to clarify the role of the cerebellum sequencing using variations on implicit versus explicit and motor versus cognitive demands across five experiments. Converging results across these studies suggest that cerebellar feedforward mechanisms may be necessary for sequencing in the implicit domain only. In the ataxia group, rhythmic tapping, rate of motor learning, and implicit sequence learning were impaired. However, for cognitive sequencing that could be accomplished using explicit strategies, the cerebellar group performed normally, as though they shifted to extra-cerebellar mechanisms to compensate. For example, when cognitive and motor functions relied on cerebellar function simultaneously, the ataxia group's motor function was unaffected, in contrast to that of controls whose motor performance declined as a function of cognitive load. These findings indicated that the cerebellum is not critical for all forms of sequencing per se. Instead, it plays a fundamental role for sequencing within the implicit domain, whether functions are motor or cognitive. Moreover, individuals with cerebellar ataxia are generally able to compensate for cognitive sequencing when explicit strategies are available in order to preserve resources for motor function.

Neuropsychiatric Symptoms as a Reliable Phenomenology of Cerebellar Ataxia.

While cerebellar ataxia (CA) is a neurodegenerative disease known for motor impairment, changes in mood have also been reported. A full account of neuropsychiatric symptomology in CA may guide improvements in treatment regimes, measure the presence and severity of sub-clinical neuropsychiatric disturbance symptomology in CA, and compare patient versus informant symptom recognition. Neuropsychiatric phenomena were gathered from CA patients with genetic and unknown etiologies and their informants (e.g., spouse or parent). Information was obtained from in-person interviews and the Center for Epidemiologic Studies Depression Scale. Responses were converted to the Neuropsychiatric Inventory-Questionnaire (NPI-Q) scores by consensus ratings. Patient NPI-Q scores were evaluated for symptom prevalence and severity relative to those obtained from healthy controls. Patient-informant NPI-Q score disagreements were evaluated. In this cohort, 95% of patients presented with at least one neuropsychiatric symptom and 51% of patients with three or more symptoms. The most common symptoms were anxiety, depression, nighttime behaviors (e.g., interrupted sleep), irritability, disinhibition, abnormal appetite, and agitation. The prevalence of these neuropsychiatric symptoms was uniform across patients with genetic versus unknown etiologies. Patient and informant symptom report disagreements reflected that patients noted sleep impairment and depression, while informants noted irritability and agitation. Neuropsychiatric disturbance is highly prevalent in patients with CA and contributes to the phenomenology of CA, regardless of etiology. Clinicians should monitor psychiatric health in their CA patients, considering that supplemental information from informants can help gauge the impact on family members and caregivers.